Field of the Invention
The present invention relates to a printing apparatus that receives and prints print data transmitted from an external apparatus.
Description of the Related Art
Recent introduction of a multi-function peripheral (hereinafter, referred to as an MFP) in a large office has increased a risk of information leakage from a printed product left in the MFP. More specifically, since many office workers now use the MFP to output printing products, there is a risk of exposing confidential information printed on a printed product output by one office worker to another office worker who should not have access to such information.
For that reason, an MFP employs a printing system known as hold printing to prevent such information leakage. In the hold printing, a document transmitted from an external apparatus such as a personal computer (PC) is not immediately printed when the document is received, but accumulated on a hard disk in the MFP as a held document. The printing is executed only when the user who has instructed the printing of a document with his or her PC goes to a place where the MFP is installed and executes a print start operation with a touch panel on the MFP. The hold printing described above can not only prevent such information leakage from the printed product mistakenly picked up or left in the MFP, but can also reduce unnecessary printing and the number of document sheets left in the MFP.
However, when documents of many users are accumulated on the hard disk in the MFP, a user has to find a document that the user has input from a great number of documents including those input by other users to execute a print start operation for the desired document. As a method for addressing this, Japanese Patent Application Laid-Open No. 2012-254618 discusses a method with which a user can easily find his or her document from the held documents. In Japanese Patent Application Laid-Open No. 2012-254618, a print data control unit of an MFP extracts user identification information from a received document, and manages the information. When a hold printing function is selected, the print data control unit displays a list of the user identification information on an operation unit of the MFP, so that the user can select his or her user identification information from the list. Then, only documents corresponding to the selected user identification information are displayed. The method frees the user from finding the document that the user has input from the great number of documents including those input by other users.
As another widely known technique, MFP login permission is given based on user authentication. Examples of such technique include a keyboard authentication method using a user name/password to be input from a touch panel, and an integrated circuit (IC) card authentication method using card information acquired from an IC card through a contactless IC card reader. In either of the authentication methods, verification of the identity of a user is performed using authentication information input by the user through a certain operation. These methods generally involve a login application (or authentication application) including a user table required for matching with authentication information input by the user.
Furthermore, a proposed login method involving no user authentication includes a method in which a login application (authentication application) displays a list of user identification information, registered in the user table, on a login screen on a touch panel. With this method, the user can easily log in by simply selecting his or her user identification information on the displayed login screen. In this login method, the user is permitted to log into the MFP without an input of personal information such as a password or card information. In other words, the method involves no strict user authentication, and is inferior to a conventional authentication method in terms of security, but has an advantage in that a login user can be identified through a simple operation. Accordingly, the login method is effective in a case where a user logs into the MFP only through an operation of selecting the user identification information, and a customized function (also referred to as a personalized function) of the MFP corresponding to the login user is provided.
Here, a description is given on how the login application displays the list of the user identification information on the login screen in the login method based on the selection of the user identification information described above.
For example, in some cases, user identification information of a user who has instructed document input with a PC (hereinafter, referred to as “document input user”) is desirably displayed on the login screen with a priority over other users. For example, it is assumed that the login application may be managing information about a great number of users including only a few document input users. Since the few document input users have instructed document input through PCs, the document input users are likely to soon log into the MFP to perform a print start operation for their documents. The user can more easily select his or her user identification information when only the identification information of such users is displayed on the login screen. In some cases, the user can more easily select his or her user identification when the documents are displayed after sorted by their received date and time.